Synthesis of enantioenriched γ-quaternary cycloheptenones using a combined allylic alkylation/Stork–Danheiser approach: preparation of mono-, bi-, and tricyclic systems
作者:Nathan B. Bennett、Allen Y. Hong、Andrew M. Harned、Brian M. Stoltz
DOI:10.1039/c1ob06189e
日期:——
A general method for the synthesis of β-substituted and unsubstituted cycloheptenones bearing enantioenriched all-carbon γ-quaternary stereocenters is reported. Hydride or organometallic addition to a seven-membered ring vinylogous ester followed by finely tuned quenching parameters achieves elimination to the corresponding cycloheptenone. The resulting enones are elaborated to bi- and tricyclic compounds with potential for the preparation of non-natural analogs and whose structures are embedded in a number of cycloheptanoid natural products.
Palladium-catalyzed asymmetric alkylation in the synthesis of cyclopentanoid and cycloheptanoid core structures bearing all-carbon quaternary stereocenters
作者:Allen Y. Hong、Nathan B. Bennett、Michael R. Krout、Thomas Jensen、Andrew M. Harned、Brian M. Stoltz
DOI:10.1016/j.tet.2011.10.031
日期:2011.12
reagents enabled divergent access to γ-quaternary acylcyclopentenes through a ringcontraction pathway or γ-quaternary cycloheptenones through a carbonyl transposition pathway. Synthetic applications of these compounds were explored through the preparation of mono-, bi-, and tricyclic derivatives that can serve as valuable intermediates for the total synthesis of complex natural products. This work complements
A Unified Approach to the Daucane and Sphenolobane Bicyclo[5.3.0]decane Core: Enantioselective Total Syntheses of Daucene, Daucenal, Epoxydaucenal B, and 14-<i>para</i>-Anisoyloxydauc-4,8-diene
作者:Nathan B. Bennett、Brian M. Stoltz
DOI:10.1002/chem.201302353
日期:2013.12.23
enone intermediate enables the enantioselective total syntheses of daucene, daucenal, epoxydaucenal B, and 14‐para‐anisoyloxydauc‐4,8‐diene. Central aspects include a catalytic asymmetric alkylation followed by a ringcontraction and ring‐closing metathesis to generate the five‐ and seven‐membered rings, respectively.